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The official name of this gene is “ceroid-lipofuscinosis, neuronal 5.”
CLN5 is the gene's official symbol. The CLN5 gene is also known by other names, listed below.
The CLN5 gene provides instructions for making a protein whose function is unknown. When produced, the CLN5 protein has extra protein segments attached and is inactive. This form is called a preprotein. For the CLN5 protein to become active, the additional segments must be removed from the preprotein, followed by additional processing steps. The active CLN5 protein is found in cell compartments called lysosomes, which digest and recycle different types of molecules.
More than 20 mutations in the CLN5 gene have been found to cause late-infantile neuronal ceroid lipofuscinosis (NCL). This condition impairs motor and mental development beginning in early childhood, causing movement disorders and a decline in intellectual function. In addition, affected children often develop recurrent seizures (epilepsy) and vision impairment. One mutation (known as Finmajor) is responsible for almost all cases of late-infantile NCL caused by CLN5 gene mutations in people of Finnish descent. The Finmajor mutation replaces the protein building block (amino acid) tyrosine with a signal to stop protein production prematurely (written as Y392X). This mutation leads to an unstable protein that is quickly broken down. Other mutations interfere with processing of the immature protein or its transport to the lysosome.
Fatty substances called lipopigments accumulate in the lysosomes of people with late-infantile NCL. These accumulations can result in cell dysfunction and eventually cause cell death, especially in brain cells, which are particularly vulnerable to damage caused by lipopigments. However, it is unclear how mutations in the CLN5 gene are involved in the buildup of lipopigments and the signs and symptoms of late-infantile NCL.
Cytogenetic Location: 13q21.1-q32
Molecular Location on chromosome 13: base pairs 76,991,923 to 77,002,516
The CLN5 gene is located on the long (q) arm of chromosome 13 between positions 21.1 and 32.
More precisely, the CLN5 gene is located from base pair 76,991,923 to base pair 77,002,516 on chromosome 13.
See How do geneticists indicate the location of a gene? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genelocation) in the Handbook.
You and your healthcare professional may find the following resources about CLN5 helpful.
You may also be interested in these resources, which are designed for genetics professionals and researchers.
See How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.
amino acid ; cell ; ceroid ; epilepsy ; gene ; juvenile ; lysosome ; motor ; mutation ; protein ; tyrosine
You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://www.ghr.nlm.nih.gov/glossary).
The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.